2 files changed, 46 insertions, 7 deletions

diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 114050dc8e28..ac71653abb77 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -321,10 +321,32 @@ static void process_chn_event(u32 relid)
 void vmbus_on_event(unsigned long data)
 {
 	u32 dword;
-	u32 maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
+	u32 maxdword;
 	int bit;
 	u32 relid;
-	u32 *recv_int_page = vmbus_connection.recv_int_page;
+	u32 *recv_int_page = NULL;
+	void *page_addr;
+	int cpu = smp_processor_id();
+	union hv_synic_event_flags *event;
+
+	if ((vmbus_proto_version == VERSION_WS2008) ||
+		(vmbus_proto_version == VERSION_WIN7)) {
+		maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
+		recv_int_page = vmbus_connection.recv_int_page;
+	} else {
+		/*
+		 * When the host is win8 and beyond, the event page
+		 * can be directly checked to get the id of the channel
+		 * that has the interrupt pending.
+		 */
+		maxdword = HV_EVENT_FLAGS_DWORD_COUNT;
+		page_addr = hv_context.synic_event_page[cpu];
+		event = (union hv_synic_event_flags *)page_addr +
+						 VMBUS_MESSAGE_SINT;
+		recv_int_page = event->flags32;
+	}
+
+
 
 	/* Check events */
 	if (!recv_int_page)
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 8e1a9ec53003..c583a0403c53 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -460,15 +460,32 @@ static irqreturn_t vmbus_isr(int irq, void *dev_id)
 	 * Hyper-V, and the Windows team suggested we do the same.
 	 */
 
-	page_addr = hv_context.synic_event_page[cpu];
-	event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT;
+	if ((vmbus_proto_version == VERSION_WS2008) ||
+		(vmbus_proto_version == VERSION_WIN7)) {
 
-	/* Since we are a child, we only need to check bit 0 */
-	if (sync_test_and_clear_bit(0, (unsigned long *) &event->flags32[0])) {
+		page_addr = hv_context.synic_event_page[cpu];
+		event = (union hv_synic_event_flags *)page_addr +
+					 VMBUS_MESSAGE_SINT;
+
+		/* Since we are a child, we only need to check bit 0 */
+		if (sync_test_and_clear_bit(0,
+			(unsigned long *) &event->flags32[0])) {
+			handled = true;
+		}
+	} else {
+		/*
+		 * Our host is win8 or above. The signaling mechanism
+		 * has changed and we can directly look at the event page.
+		 * If bit n is set then we have an interrup on the channel
+		 * whose id is n.
+		 */
 		handled = true;
-		tasklet_schedule(&event_dpc);
 	}
 
+	if (handled)
+		tasklet_schedule(&event_dpc);
+
+
 	page_addr = hv_context.synic_message_page[cpu];
 	msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;